Pipe joint



Patented June 29, 1926.

unirao STATES PATENT OFFICE.

FRED-ERICK L. FEISTHAMEL, OF LOS ANGELES, CALIFORNIA, ASSIGNOB '10 JOHN F. PENROSE, OF NEWLYOBK, N. Y. Y

PIPE

Application filed January 14, 1825.- Serial Ho. 2,881.

This invention relates to an improved type of pipe joint, and is particularly directed to a packed screw-threadedjoint especially adaptable for use in connection with well 6 casing, rotary drill-pipe, or well tubing.

-A string of well casing, which consists of lengths of easing screw-threaded to gether, may in many instances be at least four thousand feet in length, and as a casing string of such length may weigh approximately forty tons, it will be evident that the screw-threads joining the several lengths are subjected to heavy stripping strains. 1

It will also be understood that during the drilling of a well the casing is subjected to vibrations having an excessive crystalliaing efiect on such joints as are not tight. Further, well casings are subjected to heavy static pressure of the fluid column usually contained therein, this fluid having a con tained sand content which tends to work in between the screw-threads of the joints and 1 cause such wear as to render the joints more or less inefiicient and more liable to crystallization.

In the rotary system of drilling, mudladen fluid is forced down the drill stem by the slush pump under a pump pressure sometimes ashigh as 800 pounds per square inch, such tluiddischarging at the bottom of the well bore and returning to the ground surface through the well casing, and under these conditions and considering the heavy vibrations due to rotary drilling, it will be evident that even a slight looseness of any of the screw-threaded joints in either the casing strin or the drill-pipe string will be very liabe to be the cause of a parting of the string containing such loose joint.

It will thus. become apparent that it is desirable to prevent any sand-laden fluid from entering between the screw-threads of the several joints.

In view of the above, it is the object of the present invention to provide a screw-threaded ipe joint having provisions for packing su joint a ainst entrance of such fluids.

Various ot er objects and advanta es will be more fully apparent from the to lowing description oi the accompanying drawings, which form a part of this disclosure, and which illustrate apreferred form of embodiment of the invention.

Of the drawings:

Fig.1 is a vertical section through the co-- engaging ends of two pipe sections constituting a packed screw-threaded joint constructed'in accordance with the present in vention.

Fig. 2 is an enlarged partial section illustr'ating a modified form of joint, the component members being partly tightened.

Fig. 3 is a View similar to Fig. 2, showing the component members fully tightened.

Fig. 4 is a fragmentary section showing a modified form of outer packing, the component members of the joint being only partly tightened. I

Fig. 5 is a View similar to Fig; 4, showing the component members fully tightened; and Fig. 6 is an elevation of a pipe coupling and adjacent pipe ends constituting component parts of pipe joints embodying the principles of the present invention.

in thedrawings, there is shown the threaded ends of two adjacent casing sections 1 and 2 formed to provide what is usually referred to as an inserted joint, that is, the one section is screwed directly into the adjacent section without the use of an intervening collar, while in Fig. 6, there. is shown the two adjacent casin sections 1 and 2 jointed by an inter-me late coupling 3, the principles of the present invention being equall applicable in either case.

In ig. 1,'the up or end of the lower casing section 1 has aliub portion providing a shoulder 5 for engagement by an elevator, as is usually employed in oil field practice for raising or lowerlng a string of well cas ing, said end being internally screw-threaded and provided, at the base of said screw threads, with a concentric packing groove or recess 6 in which is positioned a packing ring 7 constructed of compressible material and angularly split as indicated at 8, to facilitate an easy insertion thereof into said groove. This packing ring may be constructed of an one of a wide ran e of pack- 1n material, or instance, it maybe of fiber, ru ber, composition, or one of the many ty es of hydraulic packing, or it maybe of re atively soft metal such as lead, babbitt, or

copper.

The lower end of the adjacent casing section 2 is screw-threaded for engagement into the section 1, said coengaging threads being preferably standard tapered pipe threads.- The threads on the section 2 terminate short of the lower endof said section and the pethat said ring will be entirely enclosed within its groove, as shown in Fig. 1.

In Figs. 2 and 3 there is shown a 'oint' having at its inner end the same pac ing structure as above described and which the packing ring 7' in the groove or recess 6 of the casing section 1 is radially compressed by engagement therewith of the tapered surface 9 of the casing section 2.

At the upper end of the section 2, there is formed an internal concentric recess 10 having a vertical side wall, the lower portion of said wall gradually curving inwardly to provide a cam surface 11, and

the casing section 1'? is provided above the base of its threads, with a shoulder 12, the outer diameter of which is slightly less than the major diameter of the recess 10 so that said shoulder may enter said recess.

Within the recess 10 there is positioned a ring 13 of packing material which may be of the same or of a different material than is the packing ring 7 When this ring 13 is constructed of a material which will normallyretain its ring contour, it will preferably be of rectangular contour in crosssection, as shown in Fig. 3, and in assembling the jointsaidring may be first laced withln the recess 10 or it may be sipped over the threaded end of the section 2, before the section 2 is inserted into the section 1. From an examination of Figs. 2 and 3, it will be clear that as the sections are screwed together the terminal tapered surface 9*" will engage the packing ring 7 and the shoulder or abutment 12 will engage the uppersurface of the packing ring 13, as shown in Fig. 2, and that as t e joint is furthertightened the packing ring 7 will be 'radially compressed, as previously explained, and the packing ring 13 will bodily e driven downwardly, its lower portion being turned inwardly by the cam surface 11 and radially compressed into the thread rooves of the casing section 2, as shown in Fig. 3, thus forming a fluid tight joint.

In Figs. 4 and 5, I have shown a pliable packing 13 in place of the packing ring 13, and which may be any suitable type of rope packing material, and in the use of such pliable packing it will be preferable that the sections are first assembled and partly screwed together, as shown in Fig. 4, and

the section 2*.

the packing then placed within the recess 10, a subsequent tightening of the joint causing the packing 13 to be radially compressed into the a jacent threadgrooves of It will be noted that the terminal ends of both the upper casing sections 2 and 2 are tapered inwardly and rounded so.as to have no sharp corners which would tend to catch upon the lower packing ring.

While the specific forms of embodiment herein illustrated and described are full capable of fulfilling all of the objects primarily stated, it is to be understood that I do not wish to limit the invention in this regard, for it is susceptible of embodiment in various other forms, all coming within the scope of the following claims.

I claim as my invention:

1. A rigid pipe joint comprising: a member having an internally screw-threaded end; a second member having an externally screw-threaded end for engagement into said first member; and a compressible packing ring interposed between opposed unthreaded peripheral surfaces of said members, one of said surfaces being longitudinally angled to cause radial compression of said ring during relative joint tightening translation of said members.

2. A rigid pipe joint comprising: 'a member having an internally screw-threaded end; a second member having an externally screw-threaded end for engagement into said first member, and compressible packing rings positioned respectively at opposite ends of the coengaging screw-threads between opposed peripheral surfaces of said members, said surfaces being formed to cause radial compression of sa1d rings during relative joint tightening translation of said members to seal the opposite ends of the screw-threads. v

3. A rigid pipe joint comprising: a member having -an internally screw-threaded end and provided wi h a packing groove beyond the. inner end of its threads; a compressible packing ring within said groove; a second member having an externally screw-threaded end and provided with. a

smooth longitudinally an led peripheral wall beyond said threads a apted to engage and radially compress said ring during relative joint tightening translation of the members; the extreme end of the second member being tapered or rounded to prevent said second member catching upon the ring during assemblin of the members.

In testimony whereo I have hereunto set my hand at Los Angeles, California, this 6th day of J ahuary, 1925.

FREDERICK L. FEISTHAMEL; 

